how to get tessellation from given surface

Hi All,

I am developing Creo API for getting tessellation from given surface.

I have written following code.

ProSurfaceTessellationInput input;
ProTessellation tessellation;
ProTriangle *facets;
Pro3dPnt *vertices;

ProSurfacetessellationinputAlloc(&input);
ProSurfacetessellationinputChordheightSet(input,0.0);
ProSurfacetessellationinputAnglecontrolSet(input,0.0);
ProSurfacetessellationinputStepsizeSet(input,1000);
//ProSurfacetessellationinputUvprojectionSet(input,PRO_SRFTESS_DEFAULT_PROJECTION,NULL);
ProSurfaceTessellationGet(*mProSurface,input,&tessellation);
ProTessellationFacetsGet(tessellation,&facets); //Facet List
ProTessellationVerticesGet(tessellation,&vertices); //Vertices List

I am getting wrong result so where i have done mistake ? morever how to find size of facets and vertices array?

thanks in advance